Adolph cohjst



' um, homogeneous alloys containing -which the following is in use.-

I manufacturing purposes,

known that its hardness may be increased the hardness of platinum, 'scleroscope hardness enotrn seen, or new YORK, n. Y.

ALLEY.

No Drawing.

To all wliom it may concern:

Be t known that I, AnoLrH Conn, a citizen of the United States, and a'resident of the borough of Manhattan, city, county, and

State of New'Yorlnhave invented certain new and useful Improvements in Alloys, of

a specification.

This invention relates to improvements in "ridium-platinum alloys, and its object is to improve upon alloys of this kind,.to increase their hardness and improve their physical characteristics and at the same time reduce. the r cost; Another obJect- 13 to prpvide alloys of .platinum for manufacturing pur poses which are both better and cheaper than the 1 ordinary iridium-platinumalloys now These and other objects of the invention will appear in the following specification in which I will describe my invention and the novel features of which will be set forth in appended claims.

Pure. platinum is, too soft to be used tor and it is well materially by the addition of a desired amount ofiridium. Alloys are used with the irid-iunrcontentfrom a fraction of a per cent. up to 33-?,-% of the whole. Increasingthe proportion of the iridium increases the alloy. But because of high melting point of iridimore than 33-5 iridium cannot be made. It is especially noticeable in the platinum iridium alloys which contain a large per cent. of iridium, that the alloys are not homogeneous and the tendency of the iridium to separate from the alloy is very marked.

have discovered an improved way oi hardening platinum by substituting gold for some of the iridium. This makes harder alloys of better physical characteristics. example, an alloy of 90% platinum and 10% iridium, has a scleroscope hardness of 18, while'if half of the iridium be replaced by gold, making an alloy of 90% iridium and 5% gold, the

the exceedingly alloy. The pro portions of the hardening metals may be varied- For example, it of the alloy This of course is a cheaper is composed of iridium and gold, instead of Specification of Letters Patent.

smaller amounts of iridium and j and For is increased to 21.- the proportion of. gold being half iridium and half gold,-one-quarter iridium and three-quarters gold may be used, which will produce a still harder alloy. It also follows that for any desired hardness, gold are required than of the iridium alone.

Another advantage is due to the fact that the melting point of gold is low while iridium in its pure state is almost intusible. Therefore, my platinum, iridium, gold alloys are more easily made and are more.

homogeneous and more easily soldered.

They will not tarnish or corrode, are ductilev and malleable, may be worked hot or cold and do not lose their hardness by working or re-melting.

I find decided advantages by alloying platinum with iridium up to 30% of the whole in conjunction with'%; 0 to gold. The proportions of the metals alloyed may be varied throughout these ranges to obtain the required hardness without departing from the spirit and scope of my invention, and I intend no limitations other than those imposed by the appended claims.

What I claim is:

1 An alloy of refined platinum, iridium gold with an excess of platinum.

2. An alloy of refined platinum, iridium and ggld, with 1% to of the whole, iridium. and with 2 to 15% ot the whole, gold.

An alloy ofplatinuin, iridium and gold with an excess of platinum, with the proportion of gold increased when the proportion of iridium is decreased.

t. An alloy of platinum, iridium and gold with from 1% to 30% of the whole, iridium, and with $70 to 15% of the whole, gold, with the proportion of gold increased when the proportion of iridium is decreased.

An alloy of platinum, iridium and gold with an excessof platinum, with the proportion of gold decreased when the proportion of iridium is increased.

6. An alloy of platinum, iridium and gold, with from 1% to 30% of the whole, iridium, and with to 15% of the whole,

decreased when the is increased.

--I have hereunto set of June, 191,9. ADOLPH GOHN. I

proportion of iridium In witness whereof. my hand this 5th day 4 p rateateaneea this; Application filed June 6, 1919. Serial No. 302,128.

gold, with 

